This invention relates to a shield connector provided with a noise preventing capacitor.
In order to prevent noises from passing through a plurality of connector sections of an electronic instrument or the like via electric wires, it has conventionally been executed that the electric wires are connected to a shield case or the like grounded through a plurality of capacitors.
Such a construction or arrangement is shown in FIG. 1 of the attached drawings. That is, terminal pins 3 projecting from a connector housing 1 pass respectively through stepped tubular capacitors 5, and a box-shaped bracket 7 serving as a chassis plate is covered on the terminal pins 3. The tubular capacitors 5 have pairs of inner-surface electrodes 5a and outer-surface electrodes 5b, respectively, which are soldered to the terminal pins 3 and the bracket 7. Under this condition, the terminal pins 3 are bent substantially perpendicularly to form forward ends 3a, respectively, and the forward ends 3a are soldered to a wiring pattern on a printed circuit substrate 9.
In the above-described conventional shield connector, however, it is necessary that the terminal pins 3 pass respectively through the tubular capacitors 5 and, subsequently, the terminals pins 3 are bent substantially perpendicularly. An external force is applied to the tubular capacitors 5 when the terminal pins 3 are bent. Thus, there is a fear that cracks are developed in the tubular capacitors 5 and the latter is broken. Further, bending is liable to occur in the terminal pins 3.
Furthermore, in such conventional shield connector, since it is impossible to cut off noises entering into the terminal pins 3 forward from the tubular capacitors 5, a noise cutting-off characteristic is deteriorated.
As a solution of the above-described problems, there is known an arrangement illustrated in FIGS. 2 and 3, which is disclosed in, for example, Japanese Utility Model Laid-Open No. SHO 62-12279. The arrangement is such that stepped tubular capacitors 5 are fitted from the above respectively into fitting bores 13 which are formed in a metallic chassis plate 11 mounted on a rear surface of a connector housing 1, and a plurality of terminal pins 3 projecting in a manner of being bent substantially perpendicularly from the rear surface of the connector housing 1 are inserted respectively into the tubular capacitors 5. Each of the tubular capacitors 5 has a pair of inner-surface electrode 5a and outer-surface electrode 5b which are conducted in soldering respectively to the terminal pins 3 and the chassis plate 11. The tubular capacitors 5 fitted in and supported by the chassis plate 11 are supported from their upper surfaces by a support plate 15 which is mounted on the chassis plate 11. The support plate 15 has a heat resistance and an insulation. The terminal pins 3 pass respectively through the tubular capacitors 5 through through bores 17 which are formed in the support plate 15.
Accordingly, since the latter conventional example is arranged such that the tubular capacitors 5 are fitted about and mounted on the terminal pins 3, respectively, after having being bent, no excessive external force is applied to the tubular capacitors 5, and there is no fear that cracks are developed in the tubular capacitors 5. Moreover, since forward ends of the respective terminal pins 3 are supported by the tubular capacitors 5, respectively, which are supported by the metallic chassis plate 11 and the support plate 15, it is possible to prevent bending of the terminal pins 3 from occurring. Further, since the tubular capacitors 5 are provided respectively on the forward ends of the respective terminal pins 3, a noise cutting-off characteristic of the terminal pins 3 is improved as compared with the example illustrated in FIG. 1.
However, since the terminal pins 3 are exposed to the outside substantially along the entirely, the exposed portions are apt to receive signal noises from the outside. Thus, the noise cutting-off characteristic has still been insufficient. Furthermore, the environmental resistance cannot be said as being excellent.